Produce washing system utilizing multiple energy sources

Abstract

A produce cleaning system ( 20 ) and process ( 10 ) that employs plural forms of energy in an ionic liquid-based washing system ( 22, 24, 26 ) is described. The washing system ( 22, 24, 26 ) includes employing solvents and solutes in the wash bath ( 24 ) which promote the conduction of electrical energy. The electrical energy can be applied to the produce in the wash bath ( 24 ) in various waveforms, such as a modulating wave superimposed on a carrier wave. Additionally, ultrasonic energy is employed to provide high-frequency mechanical pressure waves against the produce. The electrical energy and the mechanical energy combine to produce energy in the applicable resonant frequency range that acts to destroy or transform pathogens, dirt and synthetic molecules that may exist on the produce to either destroy them or render them harmless.

What is claimed is:  
     
       1. A method of cleaning produce, comprising the steps of: 
       immersing the produce in an energizing bath;  
       subjecting the produce to an alternating electrical waveform for a predetermined period of time in the energizing bath; and  
       subjecting the produce to an ultrasonic waveform to vibrate the produce for a predetermined period of time in the energizing bath, wherein the combination of the ultrasonic waveform and the electrical waveform applies sufficient energy to decouple and neutralize pathogens and other contaminants existing on the produce.  
     
     
       2. The method according to  claim 1 , wherein the step of subjecting the produce to the electrical waveform includes subjecting the produce to an alternating electrical waveform that includes a fundamental carrier wave and a higher frequency wave imposed on the carrier wave. 
     
     
       3. The method according to  claim 2 , wherein the step of subjecting the produce to the electrical waveform includes generating the carrier wave at a current sufficient enough to establish an electric current in the energizing bath and generating a higher frequency wave that has a frequency sufficient to provide microelectrification of bacteria and pathogens on the produce. 
     
     
       4. The method according to  claim 2 , wherein the carrier wave has a frequency in the range of 10 Hz to 100 kHz and an electrical current in the range of 1 milliamp per square centimeter to 1,000 milliamps per square centimeter in the bath. 
     
     
       5. The method according to  claim 1 , wherein the step of subjecting the produce to the electrical waveform includes sweeping the electrical waveform from a first predetermined frequency to a second predetermined frequency. 
     
     
       6. The method according to  claim 5 , wherein the step of sweeping the electric waveforms from the first predetermined ultrasonic frequency to the second ultrasonic predetermined frequency includes ramping the electrical waveform in a step like manner where each step is at a higher frequency than a previous step and is maintained at the step for a predetermined period of time. 
     
     
       7. The method according to  claim 1 , wherein the step of subjecting the produce to an ultrasonic waveform includes sweeping the ultrasonic waveform between a first ultrasonic frequency and a second ultrasonic frequency. 
     
     
       8. The method according to  claim 7 , wherein the step of sweeping the ultrasonic waveform from the first ultrasonic frequency to the second ultrasonic frequency includes ramping the ultrasonic waveform in a step like manner where each step is at a higher frequency than a previous step and is maintained at the step for a predetermined period of time. 
     
     
       9. The method according to  claim 1 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in a heated energizing bath. 
     
     
       10. The method according to  claim 9 , wherein in the step of immersing the produce in an energizing bath includes immersing the produce in an energizing bath heated to about 95° F. 
     
     
       11. The method according to  claim 1 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in a water based ionizing bath. 
     
     
       12. The method according to  claim 11 , wherein the step of immersing the produce in the ionizing bath includes immersing the produce in a bath including dissolved salts. 
     
     
       13. The method according to  claim 1 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in an acid bath having a pH less than 7. 
     
     
       14. The method according to  claim 1 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in an alkaline bath having a pH greater than 7. 
     
     
       15. A method of cleaning produce, comprising the steps of: 
       immersing the produce in a liquid-based bath;  
       subjecting the produce to an ultrasonic waveform to apply mechanical vibrations to the produce in the bath for a predetermined period of time; and  
       sweeping the ultrasonic waveform between a first ultrasonic frequency and a second ultrasonic frequency so as to decouple and disintegrate a range of various pathogens and contaminants having different sizes that may exist on the produce, and wherein  
       the step of sweeping the ultrasonic waveform between the first frequency and the second frequency includes ramping the ultrasonic waveform in a step like manner where each successive step is at a higher frequency and is maintained at that step for a predetermined period of time.  
     
     
       16. The method according to  claim 15 , wherein the step of sweeping the ultrasonic waveform between the first frequency and the second frequency includes ramping the ultrasonic waveform in a step like manner through a series of at least four distinct steps, with at least one of the steps having a frequency at least double the frequency of one of the previous steps in the series. 
     
     
       17. The method according to  claim 15 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in a heated energizing bath. 
     
     
       18. The method according to  claim 17 , wherein in the step of immersing the produce in an energizing bath includes immersing the produce in an energizing bath heated to about 95° F. 
     
     
       19. The method according to  claim 15 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in a water based ionizing bath. 
     
     
       20. The method according to  claim 19 , wherein the step of immersing the produce in the ionizing bath includes immersing the produce in a bath including dissolved salts. 
     
     
       21. The method according to  claim 15 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in an acid bath having a pH less than 7. 
     
     
       22. The method according to  claim 15 , wherein the step of immersing the produce in an energizing bath includes immersing the produce in an alkaline bath having a pH greater than 7.